The prior art has offered various cover plate assemblies for wall mounted electrical devices. The cover plate assemblies often employ externally visible fasteners. The prior art has also offered cover plate assemblies with concealed fasteners. Such cover plates are often formed of a plastic material with integral fasteners. The National Electrical Manufacturers Association has provided a standard ratio tolerance between long and short sides on a single gang wall plate of 1.4 to 1 minimum. An example of a cover plate assembly is provided in U.S. Pat. No. 9,148,005 B2.